This invention relates to a face mask suitable to be used for diving or the like.
In a face mask used for diving or the like, it is well known to connect a strap to a lens frame of the face mask by means of buckles in a length-adjustable manner as disclosed in Japanese Patent Application Publication No. 2001-218869A. It is also well known to make the buckles rotatable relative to the lens frame and thereby to improve fitness of the face mask during use thereof as disclosed in Japanese Patent Application Publication No. 1997-132193A.
In the case of the buckle rotatable face mask as disclosed in the above-cited Publication, it is easy for the wearer to adjust the strap at a desired position relative to the lens frame but the strap may shift from this desired position as the buckles unintentionally are rotated during use of the face mask. Consequently, it may be sometimes difficult to retain the strap at the adjusted position.